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A LACK of sleep doesn鈥檛 just turn children into a grumpy handful, it may听also accelerate their cellular ageing听鈥� a process that could have long-term health effects.

Telomeres 鈥� the caps at the ends of our chromosomes听鈥� get shorter every time our cells divide, and when they get too short, it is thought that cells are no longer able to divide to repair and replenish the body 鈥撎�a sign of ageing. Some small studies in adults have suggested that听sleep听might be linked to telomere length.

To find out if it is also the case in children,听听补苍诲听听at Princeton University and their team dug into a听database. It听included information on average sleep duration collected from 1567听9-year-old children from cities across the US. The听team extracted DNA from saliva samples from the children, and examined the length of听their telomeres.

They found that telomeres were shorter in children who slept less (The Journal of Pediatrics,听). 鈥淭elomere length is 1.5 per cent shorter for each hour less that children sleep per night,鈥� says James.

Short telomeres have been linked to cancer, heart disease and cognitive decline, but these children showed no signs of these diseases听鈥� probably because of their young age. However, they may have a higher risk of developing these disorders in later life, says James. 鈥淚t raises concerns.鈥�

Some research in adults suggests that too much sleep might be as bad for your health as too little. But in the children in the study, at least when it came to cell ageing, more sleep was associated with longer telomeres.

The team doesn鈥檛 know whether telomere shortening can be reversed with more sleep, but says the study reiterates the importance of getting plenty of slumber. 鈥淭he current recommendation is for such children to get between 9 and 11 hours of sleep,鈥� says James.

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This article appeared in print under the headline 鈥淐hildren who sleep less may age faster鈥�